Skill focus: Inference questions
Exercise 1: Read and choose the correct answer.
Acid rain can harm buildings, plants, and even people. Acid rain is rain that contains acidic
chemicals. It is caused by chemicals put into the environment by humans. These chemicals mixing
with water cause the acid rain that we have on Earth today.
“Acidic” means that the rain’s pH level is acidic rather than neutral or basic. A pH scale runs from
0 to 14; the lower the number, the higher the acidity. Water is right in the middle with a pH of 7.
Bleach and other cleaning fluids are usually basic. These are dangerous too because they dissolve
protein. Acids tend to taste sour and can hurt people by burning them. These acids can also erode
concrete or metal.
Obviously, rain, snow, and ice can damage buildings and forests, but acidic rain, snow, and ice make
this damage happen much faster. The famous Statue of Liberty in New York City had to be fixed
because of acid rain. Some cities cover up their statues during the winter when snow and ice stays
on the ground for a long time. Acid rain can also harm animals. Fish eggs in ponds and lakes cannot
hatch if the pH is below 5.
Question 1. What is the passage mostly about?
(A) Acid rain being harmful
(B) The pH scale and acid rain
(C) Acid in rain, snow, and ice
(D) Hydrogen ions in substances
Question 2. What does the author imply by saying “These are dangerous too...”?
(A) Bleach is not dangerous to humans.
(B) Water can be dangerous if it’s neutral.
(C) Both acidic and basic things are harmful.
(D) Basic things are more dangerous than acidic things.
Question 3: What does the author imply about rain?
(A) It should have a pH of 7.
(B) It smells like lemon juice and vinegar.
(C) It doesn’t affect fish in ponds and lakes.
(D) It is more dangerous to buildings than statues.

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Exercise 2: Read and choose the correct answer.
The hippopotamus is an animal that is native to Africa. It’s the biggest land animal in the world
except for rhinoceros and elephants, but is more closely related to whales and porpoises. Contrary
to popular belief, hippos are not friendly animals. In fact, they are one of the most aggressive
animals in Africa. Ancient African cultures admired the hippo for its bravery.
Question: What can be inferred from the passage about the hippo?
(A) They eat both plants and meat.
(B) They live with whales and porpoises.
(C) They take the first place in size among land animals.
(D) They can be dangerous to humans when they are angry.

Skill focus: Text insert questions
Exercise 1: Read and choose the correct answer.
For people with a condition called synesthesia, sound is directly linked to the sense of sight, and
they experience sounds by seeing them as colors. [A] However, different sounds sometimes remind
everyone of different colors. [B] In one study, students were asked to relate colors to different
tones of music. [C] White, yellow, and pink were associated with tones in the 4,000-Hz range; blue
and green were associated with tones in the 1,000-Hz range; and brown, gray, and black were
associated with tones in the 200-Hz range. [D]
Look at the four squares [ ] that indicate where the following sentence could be added to the
passage.
Researchers found that high-pitched notes made people think of bright colors, while low tones
brought dark colors to mind.
Where would the sentence best fit?
A. [A] B. [B] C. [C] D. [D]
Exercise 2: Read and choose the correct answer.
Langston Hughes was born in Missouri in 1902. He began to write poetry in high school and
later attended Columbia University in New York. [A] After one year at university, Hughes
commenced a nomadic life in the United States and Europe. [B] He shipped out as a merchant
marine and worked in a Paris nightclub, all the while writing and publishing poetry. [C] His prolific
literary career was launched in 1926 with the publication of his first book, The Weary Blues, a
collection of poems on African American themes set to rhythms from jazz and blues. [D] His first
novel appeared in 1930, and from that point on Hughes was known as "the bard of Harlem."
Look at the four squares [ ] that indicate where the following sentence could be added to the
passage.

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The success of this book helped finance Hughes's further education at Lincoln University in
Pennsylvania.
Where would the sentence best fit?
A. [A] B. [B] C. [C] D. [D]